Effects of aminoguanidine in murine bleomycin-induced lung fibrosis

Objective To determine the effects of aminoguanidine(AG) in murine bleomycin(BLM)induced lung fibrosis. Methods Forty-eight rats were randomly divided into 8 groups (6 rats in each group),including normal control group, BLM group,and three different doses of AG groups with their corresponding AG control groups. One day after administration of bleomycin intratracheally, aminoguanidine was given orally in each AG group once daily,according to the dosage designed. Total rats were killed two weeks later,and lung tissues were collected and frozen for examinations. Masson trichrome stain was used for Ashcroft score to estimate the degree of lung fibrosis; contents of hydroxyproline were measured by the method of alkaline hydrolization,and the expression of heat shock protein 47 (HSP47) was determined by RT-PCR.Results The degree of fibrosis dose-dependently decreased in the bleomycin groups treated with AG compared with BLM group,especially in the moderate and high dose AG-treated groups ( P＜0.01) ,as well as the contents of lung hydroxyproline and expression of HSP47 mRNA in lung tissues. No statistic difference was found between normal control group and AG control group. Conclusions AG significantly attenuates BLM-induced lung fibrosis,and it may relate to the downregulation of HSP47 expression. Key words: Aminoguanidine; Bleomycin;  Heat shock protein 47; Lung fibrosis